Herbicidal sulfonamides and their use to influence plant growth

ABSTRACT

Substituted sulfonylureas of the formula I   &lt;IMAGE&gt; I  where R1 is hydrogen, C1-C4-alkyl, C3-C4-alkenyl or alkynyl, C1-C4-haloalkyl, C3-C6-alkoxyalkyl, C4-C6-haloalkoxyalkyl or C5-C6-cycloalkyl, R2 is hydrogen, methyl or ethyl, R3 is hydrogen, halogen, methyl or methoxy, R4 is hydrogen, methyl or methoxy, X is N or C-H, and Hal is fluorine, chlorine or bromine, and alkali metal or alkaline earth metal salts thereof, with the proviso that R1 is not methyl when Hal is chlorine and X is N, a process for the manufacture of sulfonylureas of the formula I and their use as herbicides.

This application is a continuation of Ser. No. 07/464,652, filed Jan. 11, 1990, which is a continuation of Ser. No. 195,138, filed May 17, 1988, both now abandoned.

The present invention relates to novel substituted 6-halo-2-[[(1,3,5-triazin-2-yl or 1,3-pyrimindin-2-yl)aminocarbonyl]aminosulfonyl]benzoic acid esters, processes for their preparation, herbicides and plant growth regulators which contain the novel compounds as active ingredients, and a process for controlling and suppressing plant growth by means of these compounds.

European Patent EP 7687 describes sulfonylurea derivatives having a herbicidal action.

It is an object of the present invention to provide novel compounds having improved properties.

We have found, surprisingly, that this object is achieved with substituted sulfonyl ureas of the formula ##STR2## where R¹ is hydrogen, C₁ -C₄ -alkyl, C₃ -C₄ -alkenyl, or C₃ -C₄ -alkynyl, C₁ -C₄ -haloalkyl, C₃ -C₆ -alkoxyalkyl, C₄ -C₆ -haloalkoxyalkyl or C₅ -C₆ -cycloalkyl,

R² is hydrogen, methyl or ethyl,

R³ is hydrogen, halogen, methyl or methoxy,

R⁴ is hydrogen, methyl or methoxy,

X is N or C--H and Hal is fluorine, chlorine or bromine, or their alkali metal salts or alkaline earth metal salts, which compounds and salts are well tolerated by certain crops, for example Indian corn.

The end products of the formula I not only constitute a technical advance but also meet a major economic requirement, namely that they selectively control species of millet. Thus, M. Hanf in BASF Mitteilungen fur den Landbau, 1/85, Ackerunkrauter und Ackerungraser - ihre Verbreitung, Gefahrdung und wirtschaftliche Bedeutung states, on page 23: "Dioctyledonous weeds can easily by controlled with triazines, The spaces cleared were however also taken over by species of millet which, like the Indian corn itself, are resistant to this group of agents (triazines). These millets are above all species of the genera Echinochloa, Digitaria and etaria. It is now necessary to repress these species, in turn, by other specific control agents and methods."

This requirement, discussed in the light of practical experience, can now be met by the compounds according to the application.

Preferred end products of the formula I are those in which R¹ is hydrogen, C₁ -C₄ -alkyl, i.e. methyl, ethyl, preferably n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert.-butyl, C₃ -C₄ -alkenyl or C₃ -C₄ -alkynyl, such as allyl, methallyl, crotyl, but-1-en-3-yl, propargyl, but-1-yn-3-yl, or but-2-ynyl, C₁ -C₄ -haloalkyl, such as 2-chloroethyl, 2-chloro-n-propyl, 3-chloro-n-propyl, 1-chloro-but-2-yl, 2-chloroisobutyl, 4-chloro-n-butyl, chloro-tert.-butyl, 3-chloro-prop-2-yl and 2,2,2-trifluoroethyl, C₃ -C₆ -alkoxyalkyl, such as 2-methoxyethyl, 2-ethoxyethyl, 3-methoxy-n-propyl, 2-methoxy-n-propyl, 3-methoxy-n-butyl, 1-methoxy-but-2-yl, methoxy-tert.butyl, ethoxy-tert.-butyl, 2methoxy-n-butyl, 4methoxy-n-butyl, 2-ethoxy-n-propyl, 3-methoxy-n-prop-2-yl, 2-ethoxy-n-but-1-yl or 4-ethoxy-n-butyl, C₄ -C₆ -haloalkoxyalkyl, such as 2-(β-chloroethoxy)ethyl, 3(β-chloroethoxy)-n-propyl or 3-(γ-chloro-n-propoxy)n-propyl, or C₅ -C₆ -cycloalkyl, such as cyclopentyl or cyclohexyl.

The sulfonyl ureas of the formula I are obtained, for example, by (a) reacting a compound of the formula ##STR3## where R¹ has the above meaning and Hal is halogen, with a compound of the formula III ##STR4## where R², R³, R⁴ and X have the above meanings, in the presence or absence of an inert organic solvent, at a temperature conventionally used for organic reactions, namely from 0° C. to 120° C., preferably from 10° C. to 100° C. The reaction may be carried out at atmospheric or superatmospheric pressure, continuously or batchwise.

If methyl 6-fluoro-2-isocyanatosulfonylbenzoate and 2-amino-4-methoxy-6-methyl-1,3,5-triazine are used as starting materials, the course of the reaction can be represented by the following equation: ##STR5##

The sulfonyl ureas of the formula I may also be obtained (b) by reacting a sulfonamide of the formula ##STR6## where R¹ has the above meaning and Hal is halogen, with a phenyl carbamate of the formula ##STR7## where R², R³, R⁴ and X have the above meanings, in the presence or absence of an inert organic solvent and in the presence or absence of a tertiary base, at a temperature conventionally used for organic reactions, namely from 0° C. to 120° C., preferably from 10° C. to 100° C.

If, for example, methyl 6-fluoro-2-aminosulfonylbenzoate and phenyl-N-(4-methoxy-1,3,5-triazin-2-yl)carbamate are used as starting materials, the course of the reaction can be represented by the following equation: ##STR8##

The sulfonyl ureas of the formula I may also be obtained (c) by reacting a phenyl carbamate of the formula ##STR9## where R¹ has the above meaning and Hal is halogen, with an amine of the formula ##STR10## where R², R³, R⁴ and X have the above meanings, in the presence or absence of an inert organic solvent and in the presence or absence of a tertiary base, at a temperature conventionally used for organic reactions, namely from 0° C. to 120° C., preferably from 10° C. to 100° C.

If, for example, methyl 6-fluoro-2-(phenoxycarbamolsulfonyl)benzoate and 2-amino-4-methoxy-6-methyl-1,3,5-triazine are used as starting materials, the course of the reaction can be represented by the following equation: ##STR11##

Advantageously, the reaction is carried out in a solvent or diluent which is inert under the particular reaction conditions. Examples of suitable solvents are halo hydrocarbons, especially chlorohydrocarbons, e.g. tetrachloroethylene, 1,1,2,2-tetrachloroethylene, 1,1,1,2-tetrachloroethane, dichloropropane, methylene chloride, dichlorobutane, chloroform, chloronaphthalene, dichloronaphthalene, carbon tetrachloride, 1,1,1-trichloroethane or 1,1,2-trichloroethane, trichloroethylene, pentachloroethane, o-, m- or p-difluorobenzene, 1,2-dichloroethane, 1,1-dichloroethane, 1,2-cis-dichloroethylene, chlorobenzene, fluorobenzene, bromobenzene, iodobenzene, o-, m- or p-dichlorobenzene, o- or p- or m-dibromobenzene, o-, m- or p-chlorotoluene or 1,2,4-trichlorobenzen; ethers, e.g. ethyl propyl ether, methyl tert.-butyl ether, n-butyl ethyl ether, di-n-butyl ether, diisobutyl ether, diisoamyl ether, diisopropyl ether, anisole, phenetole, cyclohexyl methyl ether, diethyl ether, ethylene glycol dimethyl ether, tetrahydrofuran, dioxane, thioanisole or β, β'-dichlorodiethyl ether; nitrohydrocabons, such as nitromethane, nitroethane, nitrobenzene o-, m- or p-chloronitrobenzene or o-nitrotoluene; nitroles, such as acetonitirle, butyronitrile; isobutyronitrile, benzonitrile and m-chlorobenzonitrile; aliphatic or cycloaliphatic hydrocarbons, e.g. heptane, pinane, nonane, o-, m- and p-cymol, gasoline fractions boiling within a range from 70° C. to 190° C., cyclohexane, methylcyclohexane, decalin, petroleum ether, hexane, naphtha, 2,2,4-trimethylpentane, 2,2,3-trimethylpentane, 2,3,3-trimethylpentane or octane; esters, e.g. ethyl acetate, ethyl acetoacetate or isobutyl acetate; amides, e.g. formamide, methylformamide or dimethylformamide; ketones, e.g. acetone, methyl ethyl ketone and mixtures of the above. The solvent is advantageously used in an amount of from 100% to 2,000% by weight, preferably from 200% to 700% by weight, based on starting materials II, IV or VI.

The compounds III or V required for the reaction are in general employed in about equimolar amounts (with an excess or deficiency of, for example, 0% to 20%, based on the particular starting materials II, IV or VI). The starting materials II, IV or VI may be introduced into one of the above diluents, after which the starting material III, in the cause of reaction (a) and (c), or the starting material V in the case of reaction (b), is added.

Advantageously, however, the process for the preparation of the novel compound is carried out by taking the starting material III or V, with or without one of the above diluents, and then adding starting material II (in the reaction a) or IV (in reaction b) or VI (in reaction c).

To complete the reaction, the mixture is stirred, after combining the components, for from 20 minutes to 24 hours at from 0° C. to 120° C., preferably from 10° C. to 100° C., especially from 20° C. to 80° C.

A tertiary base, e.g. pyridine, α,βγ-picoline, 2,4-lutidine, 2,6-lutidine, 2,4,6-collidine, p-dimethylaminopyridine, 1,4-diaza[2,2,2]bicyclooctane [DABCO] or 1,8-diazabicyclop[5,4,0]-undec-7-en, in an amount of from 0.01 to 1 mol per mol of starting material IV or VI, may advantageously be used as a reaction accelerator in reaction (b) or (c).

The salts of the sulfonyl ureas obtained by reaction with a stoichiometric amount of an aqueous base or of a metal alcoholate, if appropriate in an inert organic solvent.

The end product I is isolated from the mixture resulting from reactions a-c in the conventional manner, for example by distilling off the solvent or directly by filtering off under suction. The residue obtained may be washed with water or dilute acid to remove basic impurities. However, the residue may also be dissolved in a water-immiscible solvent, the solution then being washed as described. The desired end products are thereby obtained in a pure form but can, where necessary, be purified by recrystallization or chromatography.

Compounds of the formula I, where R¹ is hydrogen, are obtained by hydrolysis of esters of the formula I, where R¹ is C₁ -C₄ -alkyl. The hydrolysis is carried out with not less than a two fold amount of a base such as sodium hydroxide or potassium hydroxide, advantageously in a solvent mixture comprising from 2 to 8 parts by weight of methanol and from 10 to 40 parts by weight of water per part by weight of the ester of the formula II, at from 30° C. to 80° C. for from 1 to 20 hours. The sulfonamidocarboxylic acids of the formula I are precipitated by acidification.

The sulfonamides required as starting materials of the formula IV may be prepared by a Meerwein reaction from 6-halo-anthranilic acid esters and subsequent reaction with ammonia.

EXAMPLE OF THE PREPARATION OF THE INTERMEDIATE METHYL 6-CHLORO-2-AMINOSULFONYL-BENZOATE

93 g of 4-chloro-1,2-benzisothiazol-3-one-1,1-dioxide were suspended in 0.8 l of methanol and stirred for 3 hours under reflux, while passing hydrogen chloride gas through the mixture. After cooling to 20° C., suction filtration and drying, 60 g of the compound shown in the title, of melting point 152° C.-153° C., were obtained. Concentration of the filtrate under reduced pressure, trituration of the residue with methyl tert.-butyl ether, filtering off under suction and drying gave 42 g of a second fraction of melting point from 144° C.-149° C.

The following compounds of the general structure shown below can either be obtained similarly or have been prepared, in those cases where physical data are shown.

    ______________________________________                                          ##STR12##                                                                     R                  m.p. (°C.)                                                                         m.p. (°C.)                                ______________________________________                                         C.sub.2 H.sub.5     97-101    129-131                                          n-C.sub.3 H.sub.7  111-113    104-107                                          i-C.sub.3 H.sub.7  145-147     84-87                                           n-C.sub.4 H.sub.9                                                              i-C.sub.4 H.sub.9                                                              sek. C.sub.4 H.sub.9                                                           CH.sub.2CHCH.sub.2 105-108                                                     CH.sub.2CCH                                                                    CH.sub.2CH.sub.2Cl 130-134    109-110                                          CH.sub.2CH.sub.2OCH.sub.3                                                                         102-104    135-136                                          CH.sub.2CH.sub.2OCH.sub.2 CH.sub.2Cl                                                              124-126                                                     Cyclohexyl                                                                     ______________________________________                                    

EXAMPLE OF THE PREPARATION OF THE INTERMEDIATE METHYL 6-CHLORO-2-ISOCYANATOSULFONYL-BENZOATE

100 g of methyl 6-chloro-2-aminosulfonyl-benzoate were suspended in 300 ml of 1,2-dichloroethane, 123 g of thionuyl chloride were added with stirring, and the mixture was slowly heated to the reflux temperature. After it had been stirred for 5 hours under reflux, it was cooled to 55° C., 1.5 ml of pyridine were added and the mixture again heated to the reflux temperature, while introducing phosgene. After 4 hours' treatment with phosgene gas, the reaction mixture was concentrated under reduced pressure and flushed with nitrogen. The oil which remained (105 g) was used, without further purification, for the subsequent stages.

EXAMPLE OF THE PREPARATION OF THE INTERMEDIATE METHYL 6-FLUORO-2-CHLOROSULFONYL-BENZOATE

108 g of methyl 6-fluoroanthranilate and 45 g of sodium nitrite in 106 ml of water were added, via 2 feed devices, to 250 ml of stirred concentrated hydrochloric acid at 5° C. over the course of 1 hour in such a way that the ester component was present in excess. After the reaction mixture had been stirred for 20 minutes at 55° C.-8° C. it was poured, in one shot, into a previously prepared solution of 53 g of sulfur dioxide, 1.7 g of copper(II) chloride and a small amount of water in 200 ml of 1,2-dichloroethane, and the resulting mixture was stirred for 10 minutes thereafter. It was then slowly heated to 50° C. and stirred for 11/2 hours while introducing 46 g of sulfur dioxide. It was then cooled to 20° C. and 5.5 g of chlorine were introduced over 20 minutes, with stirring. Stirring was then continued for 20 minutes, after which the organic phase was separated off. It was washed with water, dried over magnesium sulfate and evaporated, giving 105 g of the compound shown in the title, in the form of a brownish oil.

EXAMPLE OF THE PREPARATION OF THE INTERMEDIATE METHYL 6-FLUORO-2-AMINOSULFONYL-BENZOATE

42.5 g of ammonia gas were introduced, at 20° C.-28° C., into a stirred mixture of 252.5 g of methyl 6-fluoro-2-chlorosulfonyl-benzoate in 700 ml of anhydrous tetrahydrofuran. After the batch had been stirred for one hour at 25° C. the precipitate formed was filtered off with suction and dissolved in water, and the solution was extracted once with ethyl acetate. On acidifying the aqueous phase with concentrated hydrochloric acid, 8.8 g of 4-fluoro-1,2-benzisothiazol-3-one-1,1-dioxide of melting point 210° C.-212° C. were obtained as a by-product.

The tetrahydrofuran filtrate was concentrated, precipitated with water, the precipice taken up in ethyl acetate, again precipitated with water, filtered off with suction and dried. 186 g of the compound shown in the title, of melting point 155° C.-159° C., were obtained. 4-Fluoro-1,2-benzisothiazol-3-one-1,1-dioxide.

100 g of methyl 6-fluoro-2-aminosulfonyl-benzoate were introduced into 430 ml of 1N sodium hydroxide solution and the mixture was heated to 40° C. and stirred for a further 5 minutes. It was then acidified with concentrated hydrochloric acid and the batch stirred for 20 minutes. After filtering off the product with suction, washing it with water and drying it, 74.4 g of the compound shown in the title, of melting point 210° C.-212° C., were obtained.

EXAMPLE 1 Methyl 6-chloro-2-[[(4,6-dimethyl-1,3-pyrimindin-2-yl)aminocarbonyl]aminosulfonyl]benzoate

15 g of methyl 6-chloro-2-(isocyanatosulfonyl)-benzoate in 100 ml of absolute acetonitirle were added over 10 minutes, at room temperature, to a stirred suspension of 6.7 g of 2-amino-4,6-dimethylpyrmidine in 50 ml of absolute acetonitirle under nitrogen; the temperature rose by 6° C. After having stirred for 5 hours at 25° C., the precipitate formed was filtered off with suction, washed with 1N dihydrochloric acid and with methanol and dried. 14.2 g of the compound shown in the title, of melting point 215° C.-217° C. were obtained.

EXAMPLE 2 β-Methoxyethyl 6-fluoro-2-[[(4,6-dimethoxy-1,3,5-triazin-2-yl)aminocarbonyl]aminosulfonyl]benzoate

7.1 g of β-methoxyethyl 6-fluoro-2-isocyanatosulfonylbenzoate in 20 ml of methylene chloride were added over 10 minutes at 25° C. to a stirred mixture of 4 g of 2-amino-4,6-dimethoxy-1,3,5-triazine in 40 ml of DMF under nitrogen; the temperature rose to 32° C. After the mixture had been stirred for 14 hours at 25° C., the solvent was removed under reduced pressure and the residue was stirred with ether and twice with 3N HCL. It was then taken up in acetone, insoluble mater was separated off and the filtrate was concentrated to dryness. 7 g of the compound shown in the title, of melting point 179° C.-182° C. were obtained.

EXAMPLE 3 Sodium salt of isopropyl 6-chloro-2-[[(4,6-dimethoxy-1,3,5-triazin-2-yl)aminocarbonyl]aminosulfonyl]benzoate

4.6 g of isopropyl 6-chloro-2-[[4,6-dimethoxy-1,3,5-triazin-2-yl) aminocarbonyl]aminosulfonyl]benzoate (compound 133) were suspended in 100 ml of methanol, 1.8 g of 30% strength methanolic sodium methylate was added at 25° C. and the mixture was heated 5 minutes to 50° C. until a clear solution was obtained. After concentrating under reduced pressure, 4.7 g of the compound shown in the title, of melting point 185° C. (with decomposition) were obtained.

The following compounds were prepared in accordance with the foregoing example (in which case physical characteristics are given) or may be prepared analogously.

                  TABLE 1                                                          ______________________________________                                          ##STR13##                                                                     Example   R.sup.1             mp (°C.)                                  ______________________________________                                         4         C.sub.2 H.sub.5     198-200                                          5         n-C.sub.3 H.sub.7                                                    6         i-C.sub.3 H.sub.7   200-202                                          7         n-C.sub.4 H.sub.9                                                    8         i-C.sub.4 H.sub.9                                                    9         sec-C.sub.4 H.sub.9                                                  10        CH.sub.2CHCH.sub.2                                                   11        CH.sub.2CHCH                                                         12        CH.sub.2CH.sub.2 Cl                                                  13        CH.sub.2CH.sub.2OCH.sub.3                                            14        CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                 15        cyclohexyl                                                           ______________________________________                                    

                  TABLE 2                                                          ______________________________________                                          ##STR14##                                                                     Example   R.sup.1             mp (°C.)                                  ______________________________________                                         16        CH.sub.3            212-214                                          17        C.sub.2 H.sub.5                                                      18        i-C.sub.3 H.sub.7                                                    19        n-C.sub.4 H.sub.9                                                    20        i-C.sub.4 H.sub.9                                                    21        sec-C.sub.4 H.sub.9                                                  22        CH.sub.2CHCH.sub.2                                                   23        CH.sub.2CCH                                                          24        CH.sub.2CH.sub.2 Cl                                                  25        CH.sub.2CH.sub.2OCH.sub.3                                                                          158-160                                          26        CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                 27        cyclohexyl                                                           ______________________________________                                    

                  TABLE 3                                                          ______________________________________                                          ##STR15##                                                                     Example  R.sup.1             mp (°C.)                                   ______________________________________                                         28       CH.sub.3            213 decomp.                                       29       C.sub.2 H.sub.5     179-182                                           30       n-C.sub.3 H.sub.7   181-184                                           31       i-C.sub.3 H.sub.7   210-212                                           32       n-C.sub.4 H.sub.9                                                     33       i-C.sub.4 H.sub.9                                                     34       sec-C.sub.4 H.sub.9                                                   35       CH.sub.2CHCH.sub.2                                                    36       CH.sub.2CCH                                                           37       CH.sub.2CH.sub.2 Cl 169-171                                           38       CH.sub.2CH.sub.2OCH.sub.3                                                                          168-170                                           39       CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                                               161-164                                           40       cyclohexyl                                                            ______________________________________                                    

                  TABLE 4                                                          ______________________________________                                          ##STR16##                                                                     Example   R.sup.1             mp (°C.)                                  ______________________________________                                         41        CH.sub.3            215-217                                          42        C.sub.2 H.sub.5     210-213                                          43        n-C.sub.3 H.sub.7   195-198                                          44        i-C.sub.3 H.sub.7                                                    45        n-C.sub.4 H.sub.9                                                    46        i-C.sub.4 H.sub.9                                                    47        sec-C.sub.4 H.sub.9                                                  48        CH.sub.2CCH.sub.2                                                    49        CH.sub.2CCH                                                          50        CH.sub.2CH.sub.2 Cl                                                  51        CH.sub.2CH.sub.2OCH.sub.3                                                                          175-177                                          52        CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                 53        cyclohexyl                                                           ______________________________________                                    

                  TABLE 5                                                          ______________________________________                                          ##STR17##                                                                     Example  R.sup.1             mp (°C.)                                   ______________________________________                                         54       CH.sub.3            227-230                                           55       C.sub.2 H.sub.5     210-212                                           56       n-C.sub.3 H.sub.7   217-219                                           57       i-C.sub.3 H.sub.7   202-205                                           58       n-C.sub.4 H.sub.9                                                     59       i-C.sub.4 H.sub.9                                                     60       sec-C.sub.4 H.sub.9                                                   61       CH.sub.2CHCH.sub.2  197 decomp.                                       62       CH.sub.2CCH                                                           63       CH.sub.2CH.sub.2 Cl                                                   64       CH.sub.2CH.sub.2OCH.sub.3                                                                          173-175                                           65       CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                  66       cyclohexyl                                                            ______________________________________                                    

                  TABLE 6                                                          ______________________________________                                          ##STR18##                                                                     Example   R.sup.1             mp (°C.)                                  ______________________________________                                         67        CH.sub.3            204-206                                          68        C.sub.2 H.sub.5                                                      69        n-C.sub.3 H.sub.7                                                    70        i-C.sub.3 H.sub.7                                                    71        n-C.sub.4 H.sub.9                                                    72        i-C.sub.4 H.sub.9                                                    73        sec-C.sub.4 H.sub.9                                                  74        CH.sub.2CHCH.sub.2                                                   75        CH.sub.2CCH                                                          76        CH.sub.2CH.sub.2 Cl                                                  77        CH.sub.2CH.sub.2OCH.sub.3                                            78        CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                 79        cyclohexyl                                                           ______________________________________                                    

                  TABLE 7                                                          ______________________________________                                          ##STR19##                                                                     Example  R.sup.1             mp (°C.)                                   ______________________________________                                         80       CH.sub.3            210-214                                           81       C.sub.2 H.sub.5     193-195                                           82       n-C.sub.3 H.sub.7   178-180                                           83       i-C.sub.3 H.sub.7   205-207                                           84       n-C.sub.4 H.sub.9                                                     85       i-C.sub.4 H.sub.9                                                     86       sec-C.sub.4 H.sub.9                                                   87       CH.sub.2CHCH.sub.2                                                    88       CH.sub.2CCH                                                           89       CH.sub.2CH.sub.2 Cl 153 decomp.                                       90       CH.sub.2CH.sub.2OCH.sub.3                                                                          154-156                                           91       CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                                               149-151                                           92       cyclohexyl                                                            ______________________________________                                    

                  TABLE 8                                                          ______________________________________                                          ##STR20##                                                                     Example   R.sup.1             mp (°C.)                                  ______________________________________                                          93       CH.sub.3            190-192                                           94       C.sub.2 H.sub.5                                                       95       n-C.sub.3 H.sub.7                                                     96       i-C.sub.3 H.sub.7                                                     97       n-C.sub.4 H.sub.9                                                     98       i-C.sub.4 H.sub.9                                                     99       sec-C.sub.4 H.sub.9                                                  100       CH.sub.2CHCH.sub.2                                                   101       CH.sub.2CCH                                                          102       CH.sub.2CH.sub.2 Cl 170-171                                          103       CH.sub.2CH.sub.2OCH.sub.3                                                                          160-162                                          104       CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                 105       cyclohexyl                                                           ______________________________________                                    

                  TABLE 9                                                          ______________________________________                                          ##STR21##                                                                     Example   R.sup.1              mp (°C.)                                 ______________________________________                                         106       C.sub.2 H.sub.5      192-194                                         107       n-C.sub.3 H.sub.7    179-181                                         108       i-C.sub.3 H.sub.7    197-198                                         109       n-C.sub.4 H.sub.9                                                    110       i-C.sub.4 H.sub.9                                                    111       sec-C.sub.4 H.sub.9                                                  112       CH.sub.2CHCH.sub.2                                                   113       CH.sub.2CCH                                                          114       CH.sub.2CH.sub.2 Cl                                                  115       CH.sub.2CH.sub.2OCH.sub.3                                            116       CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                 117       cyclohexyl                                                           ______________________________________                                    

                  TABLE 10                                                         ______________________________________                                          ##STR22##                                                                     Example R.sup.1              mp (°C.)                                   ______________________________________                                         118     CH.sub.3             212-213                                           119     C.sub.2 H.sub.5      196 decomp.                                       120     n-C.sub.3 H.sub.7    196-199                                           121     i-C.sub.3 H.sub.7    199-201                                           122     n-C.sub.4 H.sub.9                                                      123     i-C.sub.4 H.sub.9                                                      124     sec-C.sub.4 H.sub.9                                                    125     CH.sub.2CHCH.sub.2                                                     126     CH.sub.2CCH                                                            127     CH.sub.2CH.sub.2 Cl                                                    128     CH.sub.2CH.sub.2OCH.sub.3                                                                           153-156                                           129     CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                   130     cyclohexyl                                                             ______________________________________                                    

                  TABLE 11                                                         ______________________________________                                          ##STR23##                                                                     Example R.sup.1              mp (°C.)                                   ______________________________________                                         131     C.sub.2 H.sub.5      202 decomp.                                       132     n-C.sub.3 H.sub.7                                                      133     i-C.sub.3 H.sub.7    218-220                                           134     n-C.sub.4 H.sub.9                                                      135     i-C.sub.4 H.sub.9                                                      136     sec-C.sub.4 H.sub.9                                                    137     CH.sub.2CHCH.sub.2                                                     138     CH.sub.2CCH                                                            139     CH.sub.2CH.sub.2 Cl  194-196                                           140     CH.sub.2CH.sub.2OCH.sub.3                                              141     CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                                                198 decomp.                                       142     cyclohexyl                                                             ______________________________________                                    

                  TABLE 12                                                         ______________________________________                                          ##STR24##                                                                     Example   R.sup.1              mp (°C.)                                 ______________________________________                                         143       CH.sub.3                                                             144       C.sub.2 H.sub.5                                                      145       n-C.sub.3 H.sub.7                                                    146       i-C.sub.3 H.sub.7                                                    147       n-C.sub.4 H.sub.9                                                    148       i-C.sub.4 H.sub.9                                                    149       sec-C.sub.4 H.sub.9                                                  150       CH.sub.2CHCH.sub.2                                                   151       CH.sub.2CCH                                                          152       CH.sub.2CH.sub.2 Cl                                                  153       CH.sub.2CH.sub.2OCH.sub.3                                            154       CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                 155       cyclohexyl                                                           ______________________________________                                    

                  TABLE 13                                                         ______________________________________                                          ##STR25##                                                                     Example   R.sup.1              mp (°C.)                                 ______________________________________                                         156       CH.sub.3             202-205                                         157       C.sub.2 H.sub.5                                                      158       n-C.sub.3 H.sub.7                                                    159       i-C.sub.3 H.sub.7    197-199                                         160       n-C.sub.4 H.sub.9                                                    161       i-C.sub.4 H.sub.9                                                    162       sec-C.sub.4 H.sub.9                                                  163       CH.sub.2CHCH.sub.2                                                   164       CH.sub.2CCH                                                          165       CH.sub.2CH.sub.2 Cl                                                  166       CH.sub.2CH.sub.2OCH.sub.3                                            167       CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                 168       cyclohexyl                                                           ______________________________________                                    

                  TABLE 14                                                         ______________________________________                                          ##STR26##                                                                     Example R.sup.1              mp (°C.)                                   ______________________________________                                         169     CH.sub.3             216-218                                           170     C.sub.2 H.sub.5                                                        171     n-C.sub.3 H.sub.7                                                      172     i-C.sub.3 H.sub.7    210 decomp.                                       173     n-C.sub.4 H.sub.9                                                      174     i-C.sub.4 H.sub.9                                                      175     sec-C.sub.4 H.sub.9                                                    176     CH.sub.2CHCH.sub.2                                                     177     CH.sub.2CCH                                                            178     CH.sub.2CH.sub.2 Cl                                                    179     CH.sub.2CH.sub.2OCH.sub.3                                              180     CH.sub.2CH.sub.2OCH.sub.2CH.sub.2 Cl                                   181     cyclohexyl                                                             ______________________________________                                    

                  TABLE 15                                                         ______________________________________                                          ##STR27##                                                                     Example         R.sup.1     mp (°C.)                                    ______________________________________                                         182             CH.sub.3                                                       183             C.sub.2 H.sub.5                                                184             n-C.sub.3 H.sub.7                                              185             i-C.sub.3 H.sub.7                                              ______________________________________                                    

                  TABLE 16                                                         ______________________________________                                          ##STR28##                                                                     Example    R.sup.1          mp (°C.)                                    ______________________________________                                         186        CH.sub.3         >300                                               187        C.sub.2 H.sub.5  >300                                               188        n-C.sub.3 H.sub.7                                                                               >300                                               189        i-C.sub.3 H.sub.7                                                   190        n-C.sub.4 H.sub.9                                                   191        i-C.sub.4 H.sub.9                                                   192        sec.-C.sub.4 H.sub.9                                                193        CH.sub.2CHCH.sub.2                                                  194        CH.sub.2CH.sub.2 Cl                                                 195        CH.sub.2CH.sub.2OCH.sub.3                                                                       167 decomp.                                        ______________________________________                                    

                  TABLE 17                                                         ______________________________________                                          ##STR29##                                                                     Example     R.sup.1        mp (°C.)                                     ______________________________________                                         196         CH.sub.3                                                           197         C.sub.2 H.sub.5                                                    198         n-C.sub.3 H.sub.7                                                  199         CH.sub.2CH.sub.2OCH.sub.3                                                                     154                                                 ______________________________________                                    

                  TABLE 18                                                         ______________________________________                                          ##STR30##                                                                     Example         R.sup.1 mp (°C.)                                        ______________________________________                                         200             CH.sub.3                                                       201             C.sub.2 H.sub.5                                                                        >300                                                   202             n-C.sub.3 H.sub.7                                              ______________________________________                                    

                  TABLE 19                                                         ______________________________________                                          ##STR31##                                                                     Example         R.sup.1 mp (°C.)                                        ______________________________________                                         203             CH.sub.3                                                                               225-228                                                204             C.sub.2 H.sub.5                                                205             n-C.sub.3 H.sub.7                                              ______________________________________                                    

The active ingredients, or herbicidal agents containing them, may be applied pre- or postemergence. If certain crop plants tolerate the active ingredients less well, application techniques may be used in which the herbicidal agents are sprayed from suitable equipment in such a manner that the leaves of the sensitive crop plants are if possible not touched, and the agents reach the soil or the unwanted plants growing beneath the crop plants (post-directed, lay-by treatment).

The amounts applied depend on the time of year, the plants to be combated and their growth stage, and vary from 0.001 to 1, and preferably from 0.005 to 0.5, kg/ha.

The herbicidal action of sulfonamides of the formula I on the growth of these plants is illustrated in greenhouse experiments described below.

The vessels employed were plastic flowerpots having a volume of 300 cm³, and which were filled with a sandy loam containing about 3.0% humus. The seeds of the tests plants were sown shallow, and separately, according to species. For the preemergence treatment, the active ingredients were applied to the surface of the soil immediately after the seeds had been sown. The compounds were emulsified or suspended in water as vehicle, and sprayed through finely distributing nozzles. The application rates were 0.015, 0.03, 0.04 and 0.06 kg of active ingredient per hectare. After the agents had been applied, the vessels were lightly sprinkler-irrigated to induce germination and growth. Transparent plastic covers were then placed on the vessels until the plants had taken root. The cover ensured uniform germination of the plants, insofar as this was not impaired by the active ingredients.

For the postemergence treatment, the plants were first grown in the vessels to a height of from 3 to 15 cm, depending on growth form, before being treated. For this treatment, either plants which had been sown directly in the pots and grown there were selected, or plants which had been grown from seedlings and were transplanted to the pots a few days before treatment. The application rates for postemergence treatment varied and were for example 0.015, 0.03, 0.06 and 0.125 kg of active ingredient per hectare. No covers were placed on the vessels in this method.

The pots were set up in the greenhouse--species from warmer areas at from 20° C. to 35° C., and species from moderate climates at 10° C. to 20° C. The experiments were run for 2to 4 weeks. During this period the plants were tended and their reactions to the various treatments assessed. The scale employed was 0 to 100, 100 denoting nonemergence or complete destruction of at least the visible plant parts, and 0 denoting no damage or normal emergence.

The influence of the treatments was assessed visually against the untreated control.

The plants used in the greenhouse experiments were weeds and crop plants for example of the following species:

    ______________________________________                                         Abbreviation                                                                               Latin name     Common name                                         ______________________________________                                         AMARE       Amaranthus     redroot pigweed                                                 retroflexus                                                        CHEAL       Chenopodium    lambsquarters                                                   album          (goosefoot)                                         CHYCO       Chrysanthemum  crown daisy                                                     coronarium                                                         CYPES       Cyperus esculatus                                                                             yellow nutsedge                                     CYPIR       Cyperus iria   rice flatsedge                                      ECHCG       Echinochloa    barnyardgrass                                                   cruss-galli                                                        IPOSS       Ipomoea spp.   morningglory                                        LAMAM       Lamium         henbit                                                          amplexicaule                                                       LOLMU       Lolium multi-  Italian ryegrass                                                florum                                                             POLAV       Polygonum      prostrate                                                       aviculare      knotweed                                            SOLNI       Solanum        black night-                                                    nigrum         shade                                               STEME       Stellaria      chickweed                                                       media                                                              TRZAS       Triticum       wheat                                                           aestivum                                                           ZEAMX       Zea mays       Indian corn                                         ______________________________________                                    

The compound of Example 118, applied postemergence at a rate of 0.125 kg/ha and preemergence at a rate of 0.06 kg/ha, selectively combated unwanted plants in wheat, which suffered no appreciable damage.

Compound no. 41 proved to be suitable for combating grassy and broadleaved plants when applied postemergence at a rage of 0.125 kg/ha and preemergence at a rate of 0.04 kg/ha. Indian corn was not damaged.

Active ingredients nos. 1, 80, 93 and 16 exhibited a considerable herbicidal action at low application rates on selected plants.

In the greenhouse, grassy and broadleaved plants were safely combated by active ingredients nos. 80, 93 and 16 applied postemergence at rates of from 0.03 to 0.06 kg/ha.

Active ingredients nos. 67 and 54 proved suitable for combating a broad spectrum of weeds, including Cyperacaea, when applied postemergence at a rate of 0.125 kg/ha.

In view of the numerous application methods available, the compounds of the invention, and herbicidal agents containing them, may be used in a large number of crops for combating unwanted plants. The following may be mentioned by way of example:

    ______________________________________                                         Botanical name      Common name                                                ______________________________________                                         Allium cepa         onions                                                     Ananas comosus      pineapples                                                 Arachis hypogaea    peanuts (groundnuts)                                       Asparagus officinalis                                                                              asparagus                                                  Brassica napus var. napus                                                                          rapeseed                                                   Brassica napus var. napobrassica                                                                   swedes                                                     Brassica napus var. rapa                                                                           turnips                                                    Camellia sinensis   tea plants                                                 Carthamus tinctorius                                                                               safflower                                                  Carya illinoinensis pecan trees                                                Citrus limon        lemons                                                     Citrus maxima       grapefruits                                                Citrus reticulata   mandarins                                                  Citrus sinensis     orange trees                                               Coffea arabica (Coffea canephora,                                                                  coffee plants                                              Coffea liberica)                                                               Cynodon dactylon    Bermudagrass                                               Elais guineensis    oil palms                                                  Fragaria vesca      strawberries                                               Glycine max         soybeans                                                   Gossypium hirsutum (Gossypium                                                                      cotton                                                     arboreum, Gossypium herbaceum,                                                 Gossypium vitifolium)                                                          Helianthus annuus   sunflowers                                                 Helianthus tuberosus                                                                               Jerusalem artichoke                                        Hevea brasiliensis  rubber plants                                              Hordeum vulgare     barley                                                     Humulus lupulus     hops                                                       Ipomoea batatas     sweet potatoes                                             Juglans regia       walnut trees                                               Linum usitatissimum flax                                                       Lycopersicon lycopersicum                                                                          tomatoes                                                   Malus spp.          apple trees                                                Manihot esculenta   cassava                                                    Medicago sativa     alfalfa (lucerne)                                          Mentha piperita     peppermint                                                 Musa spp.           banana plants                                              Nicotiana tabacum (N. rustica)                                                                     tobacco                                                     Olea europaea      olive trees                                                Oryza sativa        rice                                                       Phaseolus lunatus   limabeans                                                  Phaseolus mungo     mungbeans                                                  Phaseolus vulgaris  snapbeans, green beans,                                                        dry beans                                                  Pennisetum glaucum  pearl millet                                               Petroselinum crispum spp. tuberosum                                                                parsley                                                    Picea abies         Norway spruce                                              Abies alba          fir trees                                                  Pinus spp.          pine trees                                                 Pisum sativum       English peas                                               Prunus avium        cherry trees                                               Prunus domestica    plum trees                                                 Prunus dulcis       almond trees                                               Prunus persica      peach trees                                                Pyrus communis      pear trees                                                 Ribes sylvestre     redcurrants                                                Ribes uva-crispa    gooseberries                                               Ricinus communis    castor-oil plants                                          Saccharum officinarum                                                                              sugar cane                                                 Secale cereale      rye                                                        Sesamum indicum     sesame                                                     Solanum tuberosum   Irish potatoes                                             Sorghum bicolor (s. vulgare)                                                                       sorghum                                                    Sorghum dochna      sorgo                                                      Spinacia oleracea   spinach                                                    Theobroma cacao     cacao plants                                               Trifolium pratense  red clover                                                 Triticum aestivum   wheat                                                      Vaccinium corymbosum                                                                               blueberries                                                Vaccinium vitis-idaea                                                                              cranberries                                                Vicia faba          tick beans                                                 Vigna sinensis (V. unguiculata)                                                                    cow peas                                                   Vitis vinifera      grapes                                                     Zea mays            Indian corn, sweet corn,                                                       maize                                                      ______________________________________                                    

To increase the spectrum of action and to achieve synergistic effects, the active ingredients according to the invention may be mixed and applied together with numerous representatives of other herbicidal or growth-regulating active ingredient groups. Examples of suitable components are diazines, 4H-3,1-benzoxazine derivatives, benzothiadiazinones, 2,6-dinitroanilines, N-phenylcarbamates, thiolcarbamats, halocarboxylic acids, triazines, amides, ureas, diphenyl ethers, traizinones, uracils, benzofuran derivatives, quinolinecarboxylic acids, other cyclohexenone compounds, etc.

It may also be useful to apply the sulfonylureas of the formula I, ether alone or in combination with other herbicides, in admixture with other crop protection agents, e.g., agents for combating pests or phytopathogenic fungi or bacteria. The compounds may also be mixed with solutions of mineral salts used to remedy nutritional or trace element deficiencies. Non-phytotoxic oils and oil concentrates may also be added.

Table 1

Herbicidal action on broadleaved unwanted planes and tolerance by a crop plant on postemergence application in the greenhouse of 0.125 kg/ha of compound no. 118 according to the invention

    ______________________________________                                          ##STR32##                                                                     Test plants and damage (%)                                                     ______________________________________                                                 TRZAS   10                                                                     AMARE   95                                                                     CHEAL   98                                                                     LAMAM  100                                                                     STEME  100                                                             ______________________________________                                    

Table 2

Control of unwanted plants and tolerance by wheat; preemergence application of 0.06 kg/ha of compound 118 according to the invention

    ______________________________________                                          ##STR33##                                                                     Test plants and damage (%)                                                     ______________________________________                                                 TRZAS  10                                                                      ECHCG  90                                                                      STEME  100                                                             ______________________________________                                    

Table 3

Postemergence control of unwanted plant growth in Indian corn; comparison between a compound according to the invention (A, Example 41) ##STR34## and the active ingredient Chlorimuron-ethyl (B) disclosed in U.S. Pat. No. 4,547,215

    __________________________________________________________________________     R.sup.1                                                                             Ha1                                                                               kg a.i./ha                                                                          ZEAMX                                                                               ECHCG                                                                               LOLMU                                                                               AMARE                                                                               CHYCO                                         __________________________________________________________________________     A CH.sub.3                                                                          F  0.125                                                                               10   98   98   100  100                                           B C.sub.2 H.sub.5                                                                   H  0.03 50   95   50   100  100                                           __________________________________________________________________________

Compound 41, when applied postemergence at a rae of 0.125 kg/ha, is suitable for combating grassy and broadleaved unwanted plants without causing any appreciable damage to Indian corn. The comparative agent Chlorimuron-ethyl did combat broadleaved plants, but at as low a rate as 0.3 kg/ha the corn is damaged to a great extent without unwanted grassy plants being combated sufficiently. This comparative experiments shows that compound 41 has significant advantages.

Table 4

Herbicidal action on grassy and broadleaved plants and tolerance by Indian corn at application rates of 0.04 kg/ha of compound 41 according to the invention

    ______________________________________                                          ##STR35##                                                                     Test plants and damage (%)                                                     ______________________________________                                                 ZEAMX   0                                                                      ECHCG  90                                                                      CHYCO  98                                                                      SOLNI  95                                                              ______________________________________                                    

Table 5

Herbicidal action of compounds according to the invention; preemergence application in the greenhouse

    ______________________________________                                          ##STR36##                                                                                     Test plants and damage (%)                                     Ex. no.                                                                              Hal    R.sup.3 kg a.i./ha                                                                            ECHCG  LOLMU  CHYCO                                ______________________________________                                          1    Cl     CH.sub.3                                                                               0.03   95     98     98                                   80    Cl     OCH.sub.3                                                                              0.03   95     100    100                                  93    F      OCH.sub.3                                                                              0.06   95     90     100                                  16    F      CH.sub.3                                                                               0.06   90     98     98                                   ______________________________________                                    

Table 6

Herbicidal action of compounds according to the invention; postemergence application in the greenhouse

    __________________________________________________________________________      ##STR37##                                                                                     Test plants and damage (%)                                     Ex. no.                                                                            Hal                                                                               R.sup.3                                                                            kg a.i./ha                                                                          ECHCG                                                                               LOLMU                                                                               CHYCO                                                                               LAMAM                                                                               STEME                                      __________________________________________________________________________     80  Cl OCH.sub.3                                                                          0.03 100  98    98   98  100                                        93  F  OCH.sub.3                                                                          0.06 98   95   100  100  100                                        16  F  CH.sub.3                                                                           0.06 98   95   100  100   98                                        __________________________________________________________________________

Table 7

Control of unwanted broadleaved plants on postemergence application to the greenhouse of 0.125 kg/ha of compounds according to the invention

    __________________________________________________________________________      ##STR38##                                                                              Test plants and damage (%)                                            Ex. no.                                                                             Hal AMARE CHYCO IPOSS                                                                               LAMAM POLAV CYPIR                                    __________________________________________________________________________     F        100   100   95   95    95    100                                      Cl        98    98   98   95    90    100                                      __________________________________________________________________________ 

We claim:
 1. A substituted sulfonylurea of the formula I ##STR39## where R¹ is C₁ -C₄ -alkyl, R² is H, R³ is chlorine, R⁴ is methoxy, X is CH, Hal is fluorine or chlorine, and alkali metal and alkaline earth metal salts thereof.
 2. The sulfonylurea of the formula I as defined in claim 1, wherein R¹ is ethyl and Hal is chlorine.
 3. The sulfonylurea of the formula I as defined in claim 1, wherein R¹ is methyl and Hal is fluorine.
 4. A composition comprising a herbicidally-effective amount of a substituted sulfonylurea described in claim 1 and an agriculturally suitable carrier therefor.
 5. A composition comprising a herbicidally-effective amount of a substituted sulfonylurea described in claim 2 and an agriculturally suitable carrier therefor.
 6. A composition comprising a herbicidally-effective amount of a substituted sulfonylurea described in claim 3 and an agriculturally suitable carrier therefor.
 7. A method of combating the growth of unwanted plants which are located in cereal crops, which method comprises applying a herbicidally effective amount of a compound described in claim 1 to the unwanted plants.
 8. A method of combating the growth of unwanted plants which are located in cereal crops, which method comprises applying a herbicidally effective amount of a compound described in claim 2 to the unwanted plants.
 9. A method of combating the growth of unwanted plants which are located in cereal crops, which method comprises applying a herbicidally effective amount of a compound described in claim 3 to the unwanted plants. 